JP2823507B2 - Shaft fixed small vibration motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration motor as a silent sound source mounted on a portable wireless calling device (trade name: pager), and in particular, to an improvement of a small shaft fixed vibration motor.

[0002]

2. Description of the Related Art Conventionally, an eccentric weight W made of a tungsten alloy is disposed on an output shaft S of a cylindrical coreless DC motor M as a silent call means such as a pager as shown in FIG. There is known an apparatus that generates vibration using a difference in centrifugal force.

[0003] However, the ones which arranged eccentric weight W of the above-mentioned conventional output shaft, in the Se Tsu-up side, etc. must be consideration of the turning space of the eccentric weight W,
Due to design restrictions, costly problems have arisen, such as the need to drill and place an expensive tungsten alloy.

[0004] In order to solve such a problem, the present applicant has previously filed Japanese Patent Application No. 2-309070 (US Pat.
As shown in 55), a cylindrical coreless vibration motor without a fixed shaft output shaft has been proposed. That is, as shown in FIG. 3, there is a case in which one end of a shaft 2 is fixed to an end of a case 1 constituting a part of a housing, and the other end is fitted to a brush base 3 made of synthetic resin. A cylindrical magnet 5 made of a rare earth is fixed to the middle of the shaft 2, and a cylindrical coreless winding 6 is disposed outside the magnet 5 in the case via a gap. A pair of eccentric bearings 9 and 10 are disposed at both ends of the cylindrical coreless winding 6 via synthetic resin holders 7 and 8, and the bearings 9 and 10 rotatably support the shaft 2. . A commutator 11 is further integrated with the holder 7, and a pair of brushes 12, 13 are slidably contacted. The base ends of the brushes 12 and 13 are implanted in the brush base 3. The base end 12a of one brush is press-fitted into the bracket 4, and the base end 13a of the other brush is electrically contacted when the brush base 3 is assembled to the case, and is soldered to maintain reliability. It has become. Reference numeral 14 in the figure denotes support legs for mounting the motor on the drawing to a printed circuit board or the like.

In such a configuration, the eccentric bearing generates a centrifugal force during rotation and can generate vibration. And since this eccentric bearing is built-in, there is no design restriction on the set side, and it is convenient to use. In addition, since the eccentric bearing portions are disposed at both ends of the cylindrical coreless winding, the eccentric bearing portions receive the magnetic flux of the magnet 5 to a full extent and are extremely efficient.

[0006]

However, with the above-described structure, a problem may occur if a supporting member such as a printed circuit board to be set is thin. That is, such a motor is mounted on a printed circuit board (not shown) by supporting legs 1.
It is easy to deflect the printed circuit board into a dish when mounting using 4, 14, and after mounting the solder, the printed circuit board tries to return to the original horizontal level with the restoring force,
If the fitting between the recess 1a of the case and one end of the shaft 2 is weak,
The shaft 2 is likely to be exposed by vibration, and noise is generated. In particular, in order to shorten the overall length, the noise problem is likely to occur as the fitting margin is reduced. As a countermeasure, it is preferable to press-fit the case 1 by making the recess 1a smaller than the shaft diameter, but it is difficult to assemble because of the metal. On the other hand, it is also conceivable to perform bonding with a positive eye, but there is a problem in heat resistance at the time of soldering, and it also takes time and effort to assemble.

[0007]

SUMMARY OF THE INVENTION It is a basic object of the present invention to solve the above-mentioned problems and to prevent a contact sound between a housing (case) and a shaft at the time of rotational vibration with a simple structure so that no abnormal noise is generated. Things.

Another object of the present invention is to solve the problem of insulation between the case and the shaft.

Another object of the present invention is to improve the shock resistance against dropping and the like, and to prevent a problem in reliability even when the support legs are directly soldered to a printed circuit board or the like.

Another object of the present invention is to provide a battery-type vibration motor by providing a power supply electrode at an axial end.

[0011]

SUMMARY OF THE INVENTION A basic object of the present invention is to provide a shaft having a shaft fixed to a housing and a rotor eccentric to the shaft rotatably mounted on the shaft. In a fixed small vibration motor, a metal shaft is made of synthetic resin at both ends of the housing.
The shaft receiving part formed integrally with the
Press-fit and fix both ends of the shaft in the shaft receiving part,
The shaft and the housing are connected via a shaft receiving portion.
This can be achieved by providing electrical insulation .

[0012] Another object of the present invention, as described in claim 2 can be achieved in that the portion of the metal diaphyseal the mounting legs.

Still another object of the present invention can be attained by providing a feed electrode by projecting at least a part of a metal skeleton from at least an axial end as described in claim 3.

[0014]

According to the means for achieving the above-mentioned basic object, since the housing shaft does not come into direct contact with the housing shaft, no contact noise is generated, and the problem of insulation of the rotor winding via the shaft is eliminated.

According to the other means for achieving the object of the present invention, since the metal skeleton plays a role of reinforcement, impact resistance such as dropping can be achieved, and it can be directly mounted on the printed circuit board by the mounting legs.

According to still another means for achieving the object of the present invention, an ultra-compact dry cell type vibration motor can be provided.

[0017]

FIG. 1 is a sectional view of a main part of a first embodiment of the present invention. That is, the pipe-shaped case 15 having both open ends
A case terminal 1 in which a relatively flexible brush base 3 made of a heat-resistant synthetic resin is fitted to one end of the case terminal and a shaft receiving portion 16 also made of a heat-resistant synthetic resin is outsert-molded to the other end.
The housing H is fixed by caulking or the like. These synthetic resins have a heat resistance of 280 ° C. or higher (for example, trade name: Sumika Super LCP) so as to withstand the dipping solder, and a reinforcing metal skeleton 18 is embedded in the brush base 3, and a part thereof is formed in the axial direction. Round electrode 2
0, the electrode 21 also serves as a mounting leg in the radial direction.

The shaft 2 has a cylindrical magnet 5 fixed in the middle, and both ends thereof are press-fitted and fixed to the shaft receiving portion 16 and the shaft receiving portion 3a disposed on the brush base 3, respectively. A cylindrical coreless winding 6 is disposed outside the magnet 5 with a gap between the magnet 5 and the case 15. The cylindrical winding 6 has synthetic resin holders 7, 8 at both ends.
A pair of eccentric bearings 9 and 10 are arranged via the shaft 2, and are rotatably supported on the shaft 2 by the bearings 9 and 10. A commutator 11 is further integrated with one of the holders 7, and a pair of brushes 12, 1
3 are in sliding contact. The brushes 12 and 13 have their base ends implanted in the brush base 3 and one of the brushes 1 and 13.
The base end 12a of the second brush is press-fitted into the metal trunk 18 for reinforcement, and the base end 13a of the other brush makes electrical contact when the brush base 3 is assembled to the case 15 and is soldered to obtain certainty. .

In this embodiment, the case terminal 17 is formed of the shaft receiving portion 1 formed by outsert molding.
Play a 6 role of the reinforcing metal diaphyseal, received the shaft
Synthetic resin is disposed on the portion of the portion 16 to which the shaft 2 is fixed.
And electrically insulates the shaft 2 from the housing
Let me. In addition, a part of the case terminal 17 is exposed to the outside in the axial direction from the outsert molded shaft receiving portion 16 to form a round electrode 22, and a part of the case terminal 17 is projected in a radial direction. The mounting leg 23 is provided.

With this configuration, the mounting legs 21 and 23 can be mounted on the printed wiring board on the set side in the same manner as in the prior art.
In addition to this, as shown in FIG. 2, the mounting legs 21 and 23 can be cut to form an ultra-small dry cell type vibration motor with round electrodes 20 and 22, respectively, as shown in FIG.

[0021]

As described above, according to the present invention, the how
At both ends of the jing, a metal shaft was integrally molded with synthetic resin
A shaft receiving part is provided, and this shaft receiving part
Press-fit both ends of the shaft and fix it through the shaft receiving part.
The shaft and housing are electrically insulated.
Even if the insulation of the cylindrical coreless winding is broken,
Short to the metal shaft and even the case via the shaft
Can be prevented from easily
A part can be used as a mounting leg or a power supply electrode . I
The part where the shaft is fixed is
Finish with high accuracy because it depends on mold accuracy
And also greatly reduces the variation in fitting with the shaft
Can be . Also, a part of the metal shaft is attached to a mounting leg.
In this way, there is no need for additional components
Project from at least the axial end, and
For example, a dry cell type micro vibration motor can be obtained .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a small shaft fixed type vibration motor of the present invention.

FIG. 2 is a longitudinal sectional view showing a modification of the motor of FIG.

FIG. 3 is a vertical cross-sectional view of a conventional compact shaft-fixed vibration motor.

FIG. 4 is a perspective view of a conventional general small vibration motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 15 Case 3 Brush base 16 Shaft receiving part 17 Case terminal 18 Metal trunk for reinforcement 3a Shaft receiving part 20 Round electrode 21 Mounting leg 2 Shaft 5 Magnet 6 Cylindrical coreless winding 22 Round electrode 23 Mounting leg

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 7/065 H02K 5/08

Claims (3)

(57) [Claims] 1. A shaft fixed type small vibration motor formed by freely mounted rotating the rotor is eccentric to the shaft is fixed to the shaft to the housing, the
A metal skeleton is integrally molded with synthetic resin at both ends of the housing
Shaft receiving part is provided, and this shaft receiving part
Both ends of the shaft are press-fitted and fixed.
The shaft is electrically insulated from the housing via the section
A small-shaft fixed-type vibration motor characterized in that: 2. The small shaft fixed type vibration motor according to claim 1, wherein a part of said metal skeleton is used as a mounting leg. 3. The small-shaft fixed-vibration motor according to claim 1, wherein a part of the metal skeleton protrudes from at least an axial end to form a power supply electrode.